MKV tools: Black borders on output mp4 file - not present in source video

[TOMillr]

I'm trying to convert my dvr-ed movies into an mp4 container using the mkvtool gui. While the transcoding process seems to work well, I've noticed that the mp4 output files now have black borders on the top and bottom part of the screen which weren't present in the source file. Any idea how I might get rid of those borders as I'm just using the pass thru option for the h.264 video track?

Original mkv file:

* * * MediaInfo Mac 0.7.33.4 file analysis report.
* * * MediaInfo Mac is �2010 by Diego Massanti - http://mediainfo.massanti.com
* * * MediaInfoLib by Jerome Martinez - http://mediainfo.sourceforge.net
Created on: 11.09.2010 19:50:30 MESZ
Report for file: Moonraker.mkv

General / Container Stream #1
Total Video Streams for this File.................1
Total Audio Streams for this File.................1
Video Codecs Used.................................AVC
Audio Codecs Used.................................AC3
File Format.......................................Matro ska
Play Time.........................................2h 1mn
Total File Size...................................8.22 GiB
Total Stream BitRate..............................9 723 Kbps
Encoding Library..................................Haali DirectShow Matroska Muxer 1.10.262.12
Video Stream #1
Codec (Human Name)................................AVC
Codec (FourCC)....................................V_MPEG 4/ISO/AVC
Codec Profile.....................................Main@L 4.0
Frame Width.......................................1 440 pixels
Frame Height......................................1 080 pixels
Frame Rate........................................25.000 fps
Total Frames......................................181624
Display Aspect Ratio..............................16:9
Scan Type.........................................Inter laced
Scan Order........................................TFF
Color Space.......................................YUV
Codec Settings (Summary)..........................CABAC / 4 Ref Frames
QF (like Gordian Knot)............................0.239
Codec Settings (CABAC)............................Yes
Codec Settings (Reference Frames).................4
Video Stream Length...............................2h 1mn 4s 960ms
Video Stream BitRate..............................9 273 Kbps
Bit Depth.........................................8 bits
Video Stream Size.................................7.84 GiB (95%)
Video Stream Title................................PID 2362 Video
Color Primaries...................................BT.709-5, BT.1361, IEC 61966-2-4, SMPTE RP177
Transfer Characteristics..........................BT.709-5, BT.1361
Matrix Coefficients...............................BT.709-5, BT.1361, IEC 61966-2-4 709, SMPTE RP177
Audio Stream #1
Codec............................................. AC-3
Codec (FourCC)....................................A_AC3
Audio Stream Length...............................2h 1mn 4s 940ms
Audio Stream BitRate..............................256 Kbps
Audio Stream BitRate Mode.........................CBR
Number of Audio Channels..........................2
Audio Channel's Positions.........................Front: L R
Sampling Rate.....................................48.0 KHz
Audio Stream Delay................................59ms
Audio Stream Size.................................222 MiB (3%)
Audio Stream Title................................AC3
Audio Stream Language.............................English

Transcode mp4 file:

* * * MediaInfo Mac 0.7.33.4 file analysis report.
* * * MediaInfo Mac is �2010 by Diego Massanti - http://mediainfo.massanti.com
* * * MediaInfoLib by Jerome Martinez - http://mediainfo.sourceforge.net
Created on: 11.09.2010 20:19:03 MESZ
Report for file: Moonraker.mkv.mp4

General / Container Stream #1
Total Video Streams for this File.................1
Total Audio Streams for this File.................1
Video Codecs Used.................................AVC
Audio Codecs Used.................................AAC LC
File Format.......................................MPEG-4
Play Time.........................................4h 2mn
Total File Size...................................8.00 GiB
Total Stream BitRate..............................4 731 Kbps
Video Stream #1
Codec (Human Name)................................AVC
Codec (FourCC)....................................avc1
Codec Profile.....................................Main@L 4.0
Frame Width.......................................1 440 pixels
Frame Height......................................1 080 pixels
Frame Rate........................................25.000 fps
Total Frames......................................363246
Display Aspect Ratio..............................16:9
Scan Type.........................................Inter laced
Scan Order........................................TFF
Color Space.......................................YUV
Codec Settings (Summary)..........................CABAC / 4 Ref Frames
QF (like Gordian Knot)............................0.122
Codec Settings (CABAC)............................Yes
Codec Settings (Reference Frames).................4
Video Stream Length...............................4h 2mn 9s 841ms
Video Stream BitRate..............................4 730 Kbps
Video Stream BitRate Mode.........................VBR
Bit Depth.........................................8 bits
Video Stream Size.................................8.00 GiB (100%)
Video Stream Title................................/Users/familiemiller/Desktop/Moonraker/Moonraker.mkv.v1.h264 - Imported with GPAC 0.4.6-DEV (internal rev. 5)
Date of Original Encoding.........................UTC 2010-09-10 17:59:34
Audio Stream #1
Codec............................................. AAC
Codec (FourCC)....................................40
Audio Stream Length...............................23s 744ms
Audio Stream BitRate..............................158 Kbps
Audio Stream BitRate Mode.........................VBR
Number of Audio Channels..........................2
Audio Channel's Positions.........................Front: L R
Sampling Rate.....................................48.0 KHz
Audio Stream Size.................................457 KiB (0%)
Audio Stream Title................................/Users/familiemiller/Desktop/Moonraker/Moonraker.mkv.tempAudio.t0.aac:lang=English - Imported with GPAC 0.4.6-DEV (internal rev. 5)
Audio Stream Language.............................English
Date of Original Encoding.........................UTC 2010-09-10 18:05:08

[emmgunn]

How are you viewing your mp4 file? If you're passing through the video, it's impossible for permanent black borders to be added to the video. It would involve the creation of "black pixels" to form the borders, which could only happen if the video is re-encoded. Even if you were re-encoding, no borders should be created. It would be a waste of pixels. Then again, I've learned that impossible sometimes does happen .

What might be happening is that the pixel aspect ratio information has been messed up, so your TV or whatever viewing device your using is displaying the video with letterboxing. A settings change on your TV might fix things up. You could also use MKVtools to change the pixel aspect ratio of the mp4 file. You also could try the latest beta of MKVtools which does a better job with pixel aspect ratios.

Just thinking outside of the box, perhaps you're original has the black borders and there is a flag that tells the video player not to show them. That flag could be lost when converting to mp4. I've never heard of this, but then there are a whole bunch of things that I've never heard of .

[dizzie]

Weird. Maybe you could try AVI demux instead to change the container...